These are Small Loco style whistles threaded 1/4 x 40tpi with a nipple to suit 1/8 or 5/32 pipe. The lengths are as below:
5/8" OD x 4 3/8" Long
1/2" OD x 3 1/2" Long
3/8" OD x 2 3/4" Long
These are manufactured Items, so please allow up to 7 days for delivery.