I think they are Petco Spotted roaches (really Dubia roaches) medium 24 count they should be gut loaded with fresh veggies like mustard greens, turnip greens, dandelion leaves, collard greens, escarole lettuce, papaya, watercress and alfalfa. I would also throw in a little water soaked sea sponge to keep the roaches hydrated in the store they probly haven't gotten water at the store. Your looks like it could eat small dubias I would pick out the smallest one and see how your cham does with that 1st have tweezers on hand to pull the roach out if your Cham is having issues getting it down. My Doughnut eats large dubias all the time and they are a bit larger not by much than the space between her eyes. The only time she had an issue was with a full grown adult with wings I had to use tweezers to try to rip it out of her mouth, Doughnut would not let it go and ripped the roach into peices that went down easy.