WT-BG1
WT-BG1 fits AKG C460B-CK68 short; Audio Technica 4073A; Neumann KMR8li; Sennheiser MKH416, K6-ME66; Any shotgun mic up to 0.875" in diameter and 7.25" long.
Dimensions

Inside Diameter - .7500"

Inside Depth - 7.25"

Overall Length - 8.75"

Overall Diameter - 3.00"

WT-BG2
WT-BG2 fits AKG C451-CK8; CK98, C568EB, C460B-CK68L Audio Technica 4071A, 815, 835; Neumann KMR82i; Sennheiser K6-ME67, K3-ME80; Any shotgun mic up to 0.875" in diameter and 11.5" long.
Dimensions

Inside Diameter - .7500"

Inside Depth - 11.5"

Overall Length - 13.00"

Overall Diameter - 3.00"

WT-BG3
WT-BG3 fits Neumann KMR816; Sennheiser ME88, MKH816; Any shotgun mic up to 0.875" in diameter and 21.0" long.
Dimensions

Inside Diameter - .7500"

Inside Depth - 20.00"

Overall Length - 21.5"

Overall Diameter - 3.00"

WT-BG60
Fits Sennheiser MKH60; WT-BG70 fits Sennheiser MKH70
Dimensions

Inside Diameter - .9375"

Inside Depth - 6.00"

Overall Length - 7.5"

Overall Diameter - 3.00"

WT-BG70

Inside Diameter - .7500"

Inside Depth - 11.25"

Overall Length - 12.75"

Overall Diameter - 3.00"