Here are some comments & suggestions....
Ms. Dominant,
For a rather good discussion of the beneficial effects of requiring your husband to wear a chastity device, written by a woman, see:
Making Him Your Dream Man: Male Chastity FAQ
For "CB"-type male chastity devices (CB2000, CB3000, The Curve, CB6000) , see:
Welcome to CB-2000.com
It's best to order these from the manufacturer because (I gather) there are imitation knock-offs on the market that are cheap, poorly-made, and fit badly.
For classic-style male chastity belts that are well-made, durable (stainless steel), and would be *very* difficult for your husband to break out of, see the Tollyboy web page located here:
tollyboy products international - accessories
These run 330 to 530 pounds sterling. (Tollyboy is located in England.)
The "CB"-type chastity devices have several desirable features. They are "off the shelf," and thus do not need to be custom made. They are thus relatively inexpensive (i.e., relative to Tollyboys). They are made from a tough, durable plastic (except for the lock), and if your husband travels, the lock can be replaced with a plastic lock such that the device does not set off airport security alarms. (Obviously, a Tollyboy would loudly set off the alarm anytime your husband passes through a magnetometer-type security point. These may be encountered at places other than airports.)
Among the "CB"-type devices, the CB-6000 is the newest design, is apparently most comfortable to wear, and is more secure (harder for the wearer to remove) than the other models. Any of the "CB"-type devices can be purchased with a "points of intrigue" ring, which would make it painful for your husband to even attempt to get an erection. (A "points of intrigue" ring apparently would not injure your husband, or so I gather. This would be a consideration to look into.)
Others will have to tell you about the relative comfort, or lack thereof, of these male chastity belts and devices, and the feasibility of long-term wear. There are some on this site who could do so. I don't wear one, nor have I ever tried one.
The concept, however, of a husband being required to wear a chastity device by his wife, she being his sole key-holder, seems very erotic to me. I have not brought this up with my wife, and would have to psyche myself up substantially before doing so — since I have no reason to believe she would regard it as anything other than "really weird." I strongly suspect her response would be, "If you want to do that, go ahead, but don't expect me to have anything to do with it".... or words along those lines.
For a web site devoted to this topic see, for example:
ChastityLifestyle.com - Home
or google (or enter into whatever search engine you use) "male chastity".
Best regards—
Custer
* Comment in a letter from a British woman with long experience keeping her husband in a chastity device, in Elise Sutton's archives: "If you require your husband to wear a chastity device, cuckolding will follow like night follows day." (Perhaps it would have been more appropriate had she said, "....like day follows night" — but I'm sure you see the point.)